In an opened KeyStore window, select the certificate entry and click
on the right mouse button. From the popup menu select
Export > Export Certificate. The
certificate will be exported in the selected file. The certificate can be
exported in the following formats:
X.509 Certificate Files;
X.509 Certificate Files (PEM encrypted);
PKCS #7 Certificate Files;
PKCS #7 Certificate Files (PEM encrypted);
PKI Path Certificate Files.
Note that certificates can also be exported from signed files or from a SSL source.